Answer:
Extinction
Explanation:
When a species becomes extinct, every last specimen has died out
The partial pressure of Hydrogen gas can directly be calculated
by simply taking the difference of the overall pressure and the vapour pressure
of water. That is:
P (H2 gas) = 759.2 torr – 23.8 torr
<span>P (H2 gas) = 735.4 torr</span>
Calcium fluoride.
Ca is metal, F is non-metal, so they form ionic bond.
Ca as metal can form only positive ion. Ca in the second group, so the charge of Ca ion is 2+. Ca²⁺
F is in the 17th group, so it has 7 electrons on the last level. It is non-metal, non-metal, so it has negative charge -(8-7)=-1. "8" because on the last level cannot be more than 8 electrons. F-ion is F¹⁻.
Ca²⁺ F¹⁻
Number of positive charges should be equal to number of negative charges,
Formula of calcium fluoride
CaF2.
2 atoms Fluorine bond with Calcium.
